1. Field of the Invention
The invention generally relates to personal token cards and to environmental sensor devices.
2. Description of Related Art
Workers are sometimes required to enter environments which may be harmful such as work areas possibly having radiation or biological or chemical toxins. Rudimentary portable sensors have been developed for carrying by workers to detect exposure to certain harmful environments, such as radioactive environments. However, such portable sensors often provide only limited information such as whether the worker is exposed to more than some predetermined level of radiation. No history of exposure is recorded. Moreover, the sensor indication is often not provided in real time. Rather the sensor indication may not be provided until well after the worker has been exposed to the harmful environment. Examples include sensor badges carried by workers in potentially radioactive environments which include a radiation monitor. The radiation monitor includes a radiation sensitive material, much like photographic film, which becomes discolored sometime after the badge, and worker, have been exposed to potentially harmful levels of radiation.
Somewhat more sophisticated portable sensors have also been developed which provide a more prompt indication of potential harm, particularly for use in environments having potential chemical toxins. However, such portable sensors are often rather bulky and inconvenient to carry. As a result of the inconvenience, workers may not carry the portable sensor device thereby forfeiting any advantages otherwise gained by carrying such a device.
In view of the shortcomings of conventional portable sensor devices, it would be desirable to provide an improved portable sensor, particularly of a small and lightweight size, for use by workers, or others, potentially exposed to harmful environments. It is particularly desirable to provide an improved portable sensor with a capability of providing more than a mere indication of overall exposure, but also with the capability of recording the history of exposure and of providing alarms or other indications in real time if exposure exceeds predetermined thresholds.
Turning to a different technology, personal token cards, such as Smartcards, are becoming increasingly popular for recording and storing personal information, such as funds available within debit cards. Smartcard is a trademark of Bull CP8 Transac Corporation. A typical personal token card is about the size of a credit card and includes circuitry for inputting and outputting rudimentary information such as the amount of funds available within a debit card. Examples include telephone debit cards which are preprogrammed with a certain cash value, such as $20.00, for use in operating pay telephones. Such cards include an input/output pad for outputting a current cash value to a external system, such as a pay telephone, and for receiving a new cash value following a transaction. The cash value is stored using a non-volatile memory, such as an EPROM or flash memory. which can only be read or modified by an external system connected to the card.
Many such personal token cards conform to a form factors specified by the International Standards Organization (ISO) and include input/output pad configurations and data transmission protocols also specified by the ISO. One exemplary input/output pad configuration includes pads for power, ground, clock, input/output and reset signals. Data, corresponding for example to the cash value of a debit card, is input and output through the I/O pad using a serial data transmission protocol.
Hence, the typical personal token card merely includes a memory device for storing information recorded by an external system, such as a cash value within a debit card. Some slightly more sophisticated personal token cards have been developed which include some rudimentary logic within an integrated circuit (IC) chip such as a micro-controller chip. Examples include health care authorization cards which store medical records or security access cards which store security access codes, perhaps in an encrypted form, and include a micro-controller chip for handling encryption and de-encryption. Such security access cards may be employed by workers to access security facilities or by members of the public to access personal financial records or the like.
Turning to yet another technology, personal computer memory card international association (PCMCIA) cards are becoming increasingly popular for use with personal computer systems. PCMCIA cards, which have the shape of a credit card but somewhat thicker, often include sophisticated electronics for use in connection with a personal computer. Examples include memory devices such as hard disk drives mounted within the PCMCIA card. The PCMCIA card is inserted into a slot within a personal computer allowing the computer, and application programs running thereon, to utilize the electronics of the PCMCIA card, perhaps to access information stored therein or to otherwise utilize the electronics. Other examples include PCMCIA cards configured to provide audio capability or to interface the computer with external systems such as integrated services data network (ISDN) systems.
The inventors of the invention described herein have recognized that the aforementioned problem of providing improved personal environmental sensors may be solved by configuring a personal token card or a PCMCIA card to include a sensor for sensing environment information, such as radiation exposure, and it is to that end that the present invention is drawn.